Technical Field
The present exemplary embodiments relate to a lens driving device, a camera module and an optical apparatus.
Background
The technology described in this section is merely intended to provide background information of an exemplary embodiment of the present disclosure, and does not mean the prior art.
A camera module may include an image sensor, a PCB (Printed Circuit Board) configured to deliver electric signals to the image sensor installed on the PCB, an infrared cut-off filter configured to block light in infrared area from being incident on the image sensor, and an optical system including at least one lens configured to deliver an image to the image sensor. Here, a lens driving device configured to perform auto-focusing function and handshake compensation function may be installed in the optical system.
The lens driving device may be composed in a variety of ways. In general, a voice coil motor is commonly used in the lens driving device. The VCM (Voice Coil Motor) operates by an electromagnetic interaction between a magnet fixed in a housing and a coil unit wound on an outer circumferential surface of a bobbin coupled with a lens barrel. The VCM may perform auto-focusing function. An actuator module of such VCM may reciprocatively move in a direction parallel to an optical axis while a bobbin being moved in upward and downward directions is elastically supported by an upper and a first elastic member.
Recently, there has been a requirement to develop a lens driving device configured to swiftly detect an optimal focus position by receiving position information of a bobbin installed with a lens as a feedback.
However, in a case where a detection unit such as a Hall sensor is installed for feedback, the positioning of the Hall sensor may be difficult. Such feature of the conventional art is required to be improved.